This invention relates to a programmable calculator with a device for controlling the reading of program data, in which a program memory is so used as to effectively check the program data stored in the program memory.
Long and commonly used is the so-called "programmable calculator" which has a program memory device. An operator pushes keys of the calculator to store program data into the program memory device, whereby various arithmetic operations can be controlled and carried out according to the program data. The keyboard of the calculator of this type includes a key which is operated in order to check the program data stored in the program memory device. As the key is repeatedly depressed, the program data are read out from the memory device, the first program step, the second program step, and the third program step and so forth. Then, the steps of program are displayed by a display device one after another, one step at a time. Seeing the steps of program displayed on the display device, the operator can recognize that the right or wrong program steps have been stored into the memory device, can correct a wrong program step, or can replace a wrong program step with the correct one.
In the above method, however, the operator must push the key many times until a desired program step is displayed if many program steps have been stored into the program memory device. The known method is disadvantageous in that much time is usually required for displaying and checking a desired program step.
An object of this invention is to provide a programmable calculator with a device for controlling the reading of program data, which can read program data in various manners according to the time during which a specified key is kept depressed and which can therefore effectively check the program data.